2026 Event Schedule

As utility microgrids integrate more renewable energy generation, it is important to assess how inverter-based resources (IBRs) contribute to microgrid stability and resilience. Microgrids with high levels of intermittent solar PV generation and variable loads face specific challenges, particularly in maintaining fast voltage and frequency support. The Borrego Springs Microgrid, owned and operated by San Diego Gas & Electric Company® (SDG&E®), was the first—and remains one of the largest—utility-owned microgrids in the United States, supporting more than 3000 residents. In our latest development, we integrated a grid-forming energy storage inverter alongside multiple grid-following resources into the microgrid and local distribution control system. This microgrid was evaluated for key operational cases, including black start, islanding, and large load response.

In this panel, we will share evaluation results comparing IBR performance to that of conventional generators, highlight how hardware-in-the loop simulations conducted by National Renewable Energy Laboratory de-risked field tests, highlight key lessons learned in development and operation, and share how project insights are informing the broader deployment of microgrids across our service territory.